Apparatus for testing cement



APPARATUS FOR TESTING CEMENT Filed May 15, 1937 2 Sheets-Sheet 1 IN V ENTOR. John E. Weilen ATTORNEY.

BY WW- y 93 J. E. WEILER 2,122,765

APPARATUS FOR TESTING CEMENT Filed May 15, 1937 2 Sheets-Sheet 2 qINVENTOR.

' John E. Weller '1 BY W W.

A TTORNEY" Patented July 5, 1938 PATENT OFFICE APPARATUS FOR TESTINGCEMENT John E. Weiler, Duncan, Okla., assignor to Halliburton Oil Wellcementing Company, Duncan,

Okla.

Application May 15, 1937, Serial No. 142,840

1 Claim.

This invention relates to apparatus for testing cement or similarmaterials, and more particularly to an arrangement for determining thesetting time of cement while subjecting the same to constant agitation.

Where cement slurry is to be placed in a distant location in a fluidcondition, as in the cementing of an oil well, it is important to knowhow long the cement will remain in its fluid or plastic state beforetaking an initial 'set. It is also important to know how temperatureconditions affect the setting time of the cement.

When a cement is mixed with water and agitated, it gradually loses itsplasticity and finally reaches a state in which its form cannot bechanged without rupture. The cement is then said to be set. Long beforeit reaches a set" condition, its plasticity is so low that it would bedifiicult or impossible to pump the same. The plasticity is dependentupon a number of factors, among which may be mentioned the chemicalnature of the cement, the fineness to which it has been ground,.theamount of water used in mixing, the temperature to which it issubjected, etc. I

It is an object of the present invention to measure the degree I ofplasticity of a cement slurry while constantly agitatingthe same, thussimulating conditions met in pumping slurry into an oil well, where theslurry is agitated by the pumping operations. I

It is a further object of the present invention to devise means forsubjecting two batches of cement to the same conditions of temperatureand agitation and to note and measure. the plasticity of the two batchesso as to make comparative tests of their suitability for use in oil wellcementing or other uses where a definite knowledge of the plasticity andsetting time is required.

It is a further object of the invention to devis practical andconvenient apparatus for testing cement while continuously agitating thesame.

Other objects and advantages reside in certain novel features of theapparatus, as will be more apparent from a consideration of thefollowing description taken in connection with the accompanyingdrawings, in which:

Figure 1 is a plan view of an apparatus constructed in accordance withthe present invention and adapted to be used in making comparative testsof various cements; and

Figure 2 is a side view of the apparatus shown in Figure 1, parts of theapparatus being shown in cross-section to better illustrate theirconstruction.

' Referring to the drawings in detail, it will be seen that theapparatus there shown includes a suitable box or container ll providedwith two sliding panels or lids l2 and I3. Mounted within the lowerportion of the box H is a suitable electric heater l4 which may be usedto heat fluid, such as water, placed in the box. An electricalthermostat l5 may be centrally disposed within the box H and actuate acontrol switch contained within a casing I6, the switch being connectedinto the circuit for the heater l4 so as to regulate the temperature ofthe water or other fluid within the box H. The thermostat switch elementmay be of any known construction and controlled by means of a dial l1mounted on the side of the casing Hi, to maintain a temperature in thebox at any desired value.

In order to subject two batches of cement to the temperature prevailingwithin the box ll, two identical cement containers designated i8 and iiiare mounted on the panels l2 and I3, respectively. Since thesecontainers, together with the agitating means inside, are identical,only one will be described herein in detail.

Referring to Figure 2, it will be seen that the container I8 is ofgeneral cylindrical shape. On the bottom 20 of the container is provideda suitable thrust bearing 2|.

To mount the container [8 for rotation on the panel l2, tie rods orbolts 22 are connected to panel l2 and to a bottom supporting plate 23,the central portion of which has a bearing bolt 24 secured thereto, thisbolt cooperating with the bearing 2| on the container l8' to support thecontainer for rotation with respect to the panel l2. The container [8passes upwardly through a hole in the plate l2, the hole beingapproximately the same diameter as the container. If desired, the holein the panel l2 may be lined with suitable bearing material to hold thecontainer l8 in the proper position while it rotates.

A suitable lid is provided to close the container Hi. This may consistof a cylindrical block of metal 25 having a depending portion fittinginto the top of the container l8. The lid 25 may be connected to thecontainer l8 by means of a slot and pin connection, such as the pin 26and slot 21 shown in connection with the container is in Figure 2.

Mounted within the container l8 and supported by the bottom plate 20and. the lid 25 thereof is an agitator consisting of a shaft 28 andagitator elements or propellers 219 and 30. The agitator elements 29 arepreferably of a length approximately equal to the diameter of thecontainer l8, while the agitator elements 30 are preferably of a lesserdiameter. The outer ends of the elements 29 may be connected by means ofvertically extending'rods 3|.

To support the agitator, the shaft 28 is provided with a pointed bearing32 at its lower end, the point fitting into a socket in the bottom 20 ofthe container It. The upper end of the shaft 28 has a collar 33 fixedthereto. This collar may be attached to the shaft by means of a nut 34and a screw 35, the arrangement including a ball bearing 36 clampedbetween the nut 34 and the collar 33. The bottom portion of the collar33 is preferably provided with a flange 31 cooperating with a recess inthe lid 25 to prevent cement being tested from entering the ball bearing36. It will be noted that the nut 34 is provided with a knurled knob orhandle 38 and with a cylindrical surface 39, the purpose of which is tomeasure torque exerted upon the shaft 28, as will presently bedescribed,

In using the apparatus, the container [8 is rotated and the agitatorelements upon the shaft 28- are yieldingly held against rotationmeasuring means. When slurry or other plastic material is in thecontainer l8, and the container is rotated, some torque will betransmitted to the agitator, the amount of torque so transmitteddepending upon the degree of plasticity of the material. I To rotate thecontainer Hi, the lid 25 thereof is provided with a gear wheel 40adapted to mesh with and be driven by a worm gear 4|. An advantage ofthe present construction resides in the fact that the panel I2 whichcarries the container l8, together with its lid 25 and the gear wheel40, constitutes clutching means for driving the container l8. By-merelysliding the panel l2 in the box ll into the position shown in Figure 1,the worm 4| and the gear 49 are brought out of engagement. The containerl8 may then be readily removed from the box H. To hold the gear 49 inclutching engagement with the worm 4| a locking spool 42 is provided onthe box, the spool having a flat portion on its shaft so that the panelmay be moved past it when the spool is in the proper position, butproviding means for cooperating with the recess 43 in the panel to lockthe same in clutch engaging position.

As best shown in Figure 1, the containers l8 and I9 are both rotated bysimilar means. The container I9 is provided with a suitable gear 44identical in construction with the gear 46 and is driven by a worm 45identical with the worm 4|. The two worm gears may be mounted upon ashaft 46 extending across the box II and provided with a pulley wheel 41at one end so that the-shaft 46 may be driven by means of a suitableelectric v motor (not shown), connected by a'belt to the pulley 47. Anyconventional motor may be employed, but it should be stated that aconstant speed motor should be employed to obtain the best results.

The shaft 46 is of course provided with suitable bearings, such as areillustrated at 48, for mounting the same upon the box I I.

To yieldably hold and to indicate or measure torque exerted upon theagitators within the conby torque container adapted to tainers l8 andI9, two independent but identical devices are employed. Each of theseholding and measuring devices may include a bracket 49 fixed to thecontainer or box II. A wheel 50 is mounted on a suitable bearing on thebracket 49, the wheel having a lever 5| integral therewith which levercarries an adjustable weight 52, the lever and weight acting as apendulum. The bracket 49 may have a scale 53 fixed thereto, the scalebeing graduated in any arbitrary units. A pointer54 fixed to the wheel59 travels over this scale. The wheels 50 are connected by means ofstrings or other flexible connectors to the cylindrical portions 39 ofthe nuts 34 fixed to the shafts 28 of the agitators in the respectivecontainers. With different batches of cement are placed within thecontainers l8 and I 9 and the shaft 46 rotated, both containers l8 andI9 will be turned while the agitators therein will be yieldingly heldagainst rotation due to the weights 52. The amount the weights move willbe indicative of the torque transmitted through the bodies of cement andwill be indicated by the pointers 54.

The two batches of cement will be maintained in the same degree ofagitation and at the same temperature, since both will be subjected tothe bath within the box II. By subjecting the two batches of cement tothis degree of stiffness or plasticity of the cement may be comparedfrom time to time as the test proceeds by comparing the readings on thetwo scales 53, it being understood that the stiffer the cement withineither of the containers, the greater will be the movement of thepointers 54 over the scales 53. The scales 53 are preferably graduatedto indicate equal increments in stiffness regardless constant agitation,the.

depending upon the position of the weight. It

will thus be seen thatany two batches of cement may be compared. Astandard cement may be placed in the container l8, for example, and an.unknown cement in the container l9, andcurves plotted from the dataobtained, to show the relation of the unknown cement to the standardcement. The apparatus can, of course, also be used to test two unknowncements at the same time or to run two tests of the same cement at thesame time.

' While only oneembodiment of the invention has been shown and describedherein, it is obvious that various changes may be made in thearrangement and construction of parts without departing from the spiritof the invention or the scope of the annexed claim.

I claim:

Apparatus for testing cement or the like which includes a box having asliding panel on the top thereof, a gear mounted on the box, a holdcement mounted for rotation on the panel, said container having a gear.thereon adapted to mesh with the gear on the box, the arrangement beingsuch that in one position of the panel, the gears are in mesh and ,inanother position of the panel the gears are

